Dead-end fixture for cables



Feb, H, 1930. VARNEY 1,746,879

DEAD END FIXTURE FOR CABLES Filed May 21, 1925 3 fi M v 9% \8 IN V ENTOR.

Patented eb. 11, 1930 UNITED STATES THEODORE VARNEY, or sEwIcxL'EY,

PANY or AMERICA, or SYLVANIA PATENT OFFICE DEAD-EN D FIXTURE FOR GABLESApplication filed May 21, 1925. SeriaINo. 81,779.-

This invention is for an improvement in dead-end fixtures for compositecables, and particularly cables used in power transmission lines.

This invention is for a form "of dead-end undue strain be fixturegenerally similar to a dead-end fixture shown and described in myco-pending joint application with John P. King, Serial No. 31,233, filedMay 18, 1925. g

In high power transmission lines it is common practice to use as aconductor, a cable having a high tensile core and a relatively lowtensile highly conductive envelope. The core is usually stranded steelcable, and the envelope is usually stranded copper or aluminum.

Various forms of dead-end clamps have been devised for use in connectionwith cables of this type, but these are generally of a heavyconstruction, having a high moment of inertia.

The present invention has for its principal objects to provide adead-end fitting of a light construction which may be quickly ande'aslly applied in the field, and which will positively hold theconducting envelope and core against relative movement, so that at notime can put on the conducting envelope.

The invention may be readily understood by reference to the accompanyingdrawlngs, in which: I

Fig. 1 is a top View, partly in sectlon and partly in elevation of afitting embodymg a form of my invention to a cable.

Fig. 2 is a side elevation of the clamp and cable shown in Fig. 1.

Fig. 3 is a transverse cross-section on llne 111411 of Fig. 2.

Fig. 4 is a transverse cross-section on line IVIV of Fig. 2.

In the drawings A designates a length of composite cable having astranded high tensile core 5 of steel or other suitable material, and astranded conducting envelope 6 of copper aluminum or other suitablematerial.

The fitting includes a suitable element 7 for attachment to the steelcore of the cable, and a second element 8 for attachment to theconducting envelope. As shown, the eleefiective, the sleeve ment 7 is inthe form of a cone of steel or other suitable material, having a conicalcavity 9 therein, tapering toward the cable engaging end of the cone.Projecting longitudinally from the larger end of the conical body areparallel spaced apart lugs 10, so that the entire element 7 is in theform of a clevis.

The member 8 is preferably formed of aluminum or other light materialthat is a good electrical conductor. It has a main sleeve portion 11which is expanded at 12 to receive the conical element 7, and extendingbeyond the expanded portion are lugs 13 that overlie lugs 10. Theelement 8 is therefore, also, of a clevis like formation. Passingthrough registering holes in lugs 10 and 13 1s a pin or bolt 14 to whichthe eye of an insulator string or other supporting element, not shown,may be attached.

Depending from the body 8 is an integral lug 15, which is carefullymachined to which a connector 16 may be fitted and attached. Thisprovides a simple and efiicient manner of connecting jumpers in atransmission line, or lead-in wires at terminals of the line.

In applying a fitting to the cable, part of the envelope 6 is cut awayto expose the end portion of the steel core 5. The element 8 is thenslipped over the cable and moved back out of the way. The end of thestranded steel core is. then inserted into the conical cavity of element7 and the strands spread apart. Zinc or other metal is then flowed intothe cavity around the strands, thereby firmly connecting the steel corewith the element 7.

After this has been done, element 8 is moved forward into position,where it embraces the element 7 and the pin 14 is passed through theregistering holes in the extensions 10 and 13 of the respective members.This effectively holds the twoelements against relative movement. Thesleeve portion 11 of the outer element 8 is then pressed tightly ontothe stranded conducting envelope. To facilitate this operation, andrender it more portion is of such a shape that it can be compressed. Forinstance, it may have integral bosses thereon, as shown in thedottedlines of Fig. 2, showing the original form of the metal. This is similarto a practice now followed in joining the ends of cables, and theportable hydraulic press used in the field in making cable joints can beused in pressing the sleeve portion 11 as-will be readily appreciated bythose skilled in the art.

The fitting as thus produced is light, easily handled, easilymanufactured, and can be readily and conveniently applied in the field.Furthermore, it absolutely prevents relative slippage between the steelcore and the conducting envelope in such manner that the strain is neverput on the conducting envelope rather than the steel core.

An important advantage of its reduced mass is its low moment of inertia,whereby it does not have as great a tendency as heavier fittings toreflect mechanical vibrations of the span back into the span, therebyensuring a longer life of the cable by reducing the tendency of themetal to become fatigued at or adjacent the fitting.

While I have illustrated one specific form of the invention for thepurpose of illustration, it will be understood that various changes maybe made within the spirit of the invention, and such changes arecontemplated under the appended claims.

I claim as my invention:

1. A dead-end fitting for composite cables, including an inner memberfor attachment to the core of a composite cable, an outer memberembracing the inner one for attachment to the conducting envelope of acomposite cable, and means for attachment of a supporting elementthereto, said means positively connecting the inner and outer membersagainst relative longitudinal movement.

2. Adead-end fitting for composite cables including an inner member forattachment to the core of a composite member, an outer member in whichthe inner member is slidably received for attachment to the outerenvelope of a composite cable, and means for attachment of a supportingelement thereto, said means engaging each of the two members for holdingthem against relatively longitudinal movement.

3. A dead-end fitting including an inner clevis member having anextension thereon adapted to receive the end of the core of acompositecable, a second clevis like member embracing the first and having anextension rojecting beyond the extension of the first or engagement withthe exterior of a composite cable, and a common pin passed through thetwo clevis members.

, 4. A dead-end fitting for composite cables including an inner steelmember for engagement with a cable, an outer sleeve-like memberembracing the inner one, and-formed of a good electrical conductor, saidsleeve being extended beyond the inner member to engage the exterior ofa composite cable, a connect.

end 0 the core projectingbeyond the end of the envelope, of a dead-endfitting including an inner member having a socket in which the end ofthe core is secured and a forward extension, an outer member having asleeve portion engaging the end portion of the composite cable andembracing the inner member, said outer member having a forward extensionembracing the forward extension of the inner member, and a bolt passedthrough the extensions of the two members.

6. The combination with a composite cable having a high tensile core anda conducting envelope,'the end of the core projecting beyond the end ofthe envelope, of a socket member of high strength into which the saidprojecting end of the core extends and is secured, said socket memberhaving a clevis-like extension thereon, a conducting sleeve membersurrounding the said socket member, and secured to the exterior of thecomposite cable, said sleeve member having a clevis-like extensionoverlying the similar extension of the socket member, and a common pinpassing through the extension of both members.

7. The combination with a composite cable having a high tensile core anda conducting envelope, the end of the core projecting beyond the end ofthe envelope, of a socket member of 1 high strength into which the saidprojecting end of the core extends and is secured, said socket memberhaving a'clevislike extension thereon, a conducting sleeve membersurrounding the said socket member, and secured to the exterior of thecomposite cable, said sleeve member having a clevis-like extensionoverlying the similar extension of the socket member, a common pinpassing through the extensions of both members, said conducting sleevemember having an integral connecting lug depending therefrom.

In testimony whereof I aflix my signature.

THEODORE VARNEY.

